Where to get Carburator Jet for engine?

[StrontiumEthics]

Im having a slight problem. I'm not to sure where I can get a smaller jet for my engine? I;m pretty sure we start off stock with a 70mm jet but I want to bring it down to like 65mm or so. because when I turn off my petcock while riding my engine seems starts to FLY! I am aware that I have to probally go to Dellorto but not to sure which one...

 

[Ghost0]

Here is where to get them.
http://www.dellortodirect.com/index.php?main_page=index&cPath=12_14&sort=20a&page=7